“The spiritual person judges all things, but is himself to be judged by no one. ‘For who has understood the mind of the Lord so as to instruct him?' But we have the mind of Christ.” - 1 Corinthians 2:15-16
The spiritual person is not the one in position or holding an office in a church, nor a perfect believer without sin - for if that would be the case, then there will be no ‘spiritual person’ here on earth because his place would be in heaven. The spiritual person is someone who was born of the Spirit (John 3), his being regenerated through the gospel of Christ and he lives the truth and walks in faith.
He judges all things, not that he has knowledge of all things in nature but things that are spiritual. He discerns the foolishness of this world, the truth from error, the voice of God from the voice of strangers. He knows when the gospel is preached and when it is distorted. He never compromises the truth with unwarranted claims.
The greatest mystery that the world cannot understand is the greatness of the divine salvation that Christ provided for many. Thus the verse,
"What no eye has seen, nor ear heard,
nor the heart of man imagined,
what God has prepared for those who love him"
1 Corinthian 2:9
He has the mind of Christ… for the Word which is Christ and the Spirit who illuminates the Word are in him. He is humbled by the truth so does not fear to speak out the truth... for the sake of love and for the glory of God.